A quote that comes back within a day should be treated as a warning, rapid mvp development not a service level. An experienced provider returns clarifying questions before any number: about who owns the data and what happens on failure. A supplier that commits to a figure without asking anything is guessing, and the gap resurfaces as a change order — on your budget.
Be wary of any distance between the engineers on the sales call and the hire remote golang developers actually assigned. Insist on specific people rather than roles in the statement of work, with a provision about substitutions. A vendor that only offers abstract roles and never names people is preserving the option to staff you with whoever is free.
Ask for the source repository from day one. A partner that hands over nothing between demos is inviting you to take delivery on faith. Daily commits tell you how many people are really working far better than any status report. The same holds for the automated test suite: if there is no pipeline, quality claims remain nothing more than words.
Loose phrasing around IP is never an accident. The document needs to state in plain terms that all deliverables belong to your company on payment. Check also the governing law and how payments are structured: heavy prepayment with no milestone tied to it eliminates any leverage you would otherwise keep.
Finally, pay attention to the working rhythm. Establish what overlap there will be with your timezone, who is expected to answer day-to-day questions and docker development company within what time. Four hours of overlap generally works; zero overlap converts each small question into a day of delay. Careless writing in the sales phase will not improve once the work starts.